1. Field of the Invention
The present invention pertains to perforated, light admitting window blinds and similar coverings which provide for light transmission and sufficient transparency while reducing heat loads or losses with respect to the window covered by the blinds.
2. Background
In the art of window coverings, including vertical and horizontal blinds or louvers, it is particularly desirable to provide coverings which are sufficiently transparent to permit virtually unrestricted visibility through the coverings from inside a building while at the same time having a sufficient degree of opacity to provide privacy. Such coverings should also be capable of minimizing thermal loads imposed on the interior of the building or to prevent heat losses from the building.
Although certain types of perforated window coverings have been developed in the prior art these coverings do not minimize heat loss from the building interior or, conversly, minimize thermal loading on the building interior from the exterior environment through the window covered by such types of blinds or similar coverings. Conventional window coverings such as horizontal venetian blinds may, in fact, increase the flow of air over the surface of the window across which the blinds are disposed to actually increase thermal losses with respect to the building interior.
Accordingly, with the increased costs associated with heating and cooling building interiors there has been an acute need for improved window coverings which are capable of permitting at least daytime viewing of the outside while reflecting a substantial amount of heat and glare, maintaining a level of opacity from outside for privacy and still further providing minimal thermal losses with respect to the building interior. In this regard, the present invention provides an improved window covering having perforations which provide sufficient light transmission so as to permit substantially unrestricted visual perception through the window while minimizing thermal losses through the window.